1. Field of the Invention
The present invention relates to a joint device and, in particular, to a joint device which is used to connect a hose for fuel supply with a delivery pipe and to a simple and easy hose joint structure which can be assembled with no use of tools.
2. Description of the Conventional Art
In recent years, in an automotive engine, there has been used a electronic control fuel injection device which controls the supply of fuel by use of a computer.
In the electronic control fuel injection device, the computer inputs signals relating to the amount of air inhaled, the number of revolutions of the engine or engine speed, the water temperature, the temperature of the inhaled air, the degree of opening of a throttle, the oxygen density in the exhaust air and the like, and the computer also operates and outputs the optimum amount of injection of the fuel corresponding to the running conditions. And, in accordance with the control signals from the computer, injectors provided in the respective cylinders are controlled so that the fuel can be injected into the respective cylinders from the injectors with the optimum fuel injection amounts. This can improve the fuel efficiency, purify the exhaust gas, and improve the drivability.
The delivery pipe holds the respective injectors together, has a function to distribute the fuel to be supplied from a fuel pump to the respective injectors, and is fixed to the neighborhood of the engine and is use there.
To one end of this delivery pipe 74, as shown in FIG. 1, there is fixed a hose 75 which is connected to the fuel pump through an ring joint 73, gaskets 77 and 78, and a bolt 76. The fuel that is supplied from the hose 75 is allowed to pass from the ring joint 73 through a fuel passage formed in the delivery pipe 74, and is distributed into the respective injectors.
Specifically, as shown in FIG. 1, in a conventional joint device, there is used a so called ring union. In the ring union, one end of a pipe 71 is connected with a nipple 72, while the other end of the pipe 71 is connected with a side hole 73a formed in the side surface of a ring 73. The nipple 72 and ring 73 are manufactured by machining and they are strongly jointed by brazing to the pipe 71. Also, a fuel hose 75 is connected to the pipe 71 through the nipple 72. Further, in the central portion of the ring 73, there is opened up a central hole 73b which is in communication with the side hole 73a as well. And, use of the ring 73 allows the ring union to be connected to the delivery pipe 74.
In particular, a bolt with a hole 76 is positioned in the central hole 73b of the ring 73, that is, in the upper portion of a communication hole 74a formed in the delivery pipe 74. And, the bolt with a hole 76 is threadedly engaged with the communication hole 74a of the delivery pipe 74, whereby the ring union can be strongly fixed to the delivery pipe 74. Two rotation preventive plates (not shown) are separately mounted on the side surface of the ring 73 and on one side surface of the delivery pipe 74, so that the relative rotation between the ring 73 and delivery pipe 74 can be restricted by the rotation preventive plates. And, fuel from a fuel tank (not shown) is supplied from the fuel hose 75 through the nipple 72 and pipe 71 to the ring 73, and is then guided through the interior of the bolt with a hole 76 into the delivery pipe 74 and finally into an injector.
However, in the above-mentioned conventional joint device, it takes much time and labor to manufacture the ring union. That is, the ring 73 and nipple 72 require operations to cut or machine their rod materials. Also the ring 73 and pipe 72 require a jointing operation such as a brazing operation or the like as shown in FIG. 2. Further, in order to connect the ring union with the delivery pipe 74, there are necessary many parts such as the bolt with a hole 76 and the like, which results in the high costs. In addition, parts such as the rotation preventive plates and the like must be separately mounted to prevent the relative rotation between the ring 73 and delivery pipe 74.
Further, to connect the ring joint 73 to the delivery pipe 74, it is necessary to fasten the bolt 76, that is tools such as a spanner and the like are necessary, which increases the man-hours for assembly.
As a technique to solve the above-mentioned drawbacks, for example, there is known a technique which is disclosed in Unexamined Japanese Patent Publications (Kokai) 6-50468 and 6-50469. In this technique, as shown in FIG. 3, a pipe 81 is bent formed in a substantially right-angled shape, a metal cap portion 82 is formed in one end of the pipe 81, and a hose connecting portion (not shown) is formed in the other end thereof. A fixing clip 84 is mounted on a given portion of the pipe 81 in the neighborhood of the metal cap portion 82. The fixing clip 84 includes two securing portions 85 on both sides thereof and two claws 85a are formed integrally with the respective lower ends of the securing portions 85. Also, if the claws 85a are secured to the hitch portions 87 of a delivery pipe 86 and the metal cap portion 82 is fitted into a communication hole 88 formed in the delivery pipe 86, then the pipe 81 can be fixed to the delivery pipe 86. As a result of this, the pipe 81 can be positioned with respect to the delivery pipe 86 in the vertical direction and in the horizontal direction.
The above-mentioned conventional technique not only can omit the machining step and the brazing operation but also can reduce the number of parts. As a result of this, a mounting operationability can be improved remarkably as well as the cost of the joint device can be reduced.
However, in the above-mentioned conventional technique, the portion of the pipe 81 to be fixed by the fixing clip 84 is sometimes different from the position of the metal cap portion 82 to be fitted into the communication hole 88. That is, in come cases, the metal cap portion 82 itself is not fixed. For this reason, when a stress is applied to the pipe 81, then there is a danger that the metal cap portion 82 can be caused to wobble due to the stress applied.
Also, in the conventional technique, the claws 85a of the securing portions 85 respectively extending on the two sides of the fixing clip 84 are hitched on the hitch portions 87 of the delivery pipe 86 having a given width, thereby fixing the fixing clip 84. For this reason, the distance between the mounting portion of the fixing clip 84 to the pipe 86 and the claw 85, that is, the securing portion 85 itself is relatively long. Thus, when a stress is applied to the pipe 81, then the securing portions 85 are flexed to thereby cause the pipe 81 to wobble.